Aeration System Design for Flat Grain Storages with an Expert System

Abstract

An expert system, Aeration System Design (ASD), was developed for the design of aeration systems for farm-sized flat grain storages. ASD requests information about the storage problem from a user and generates a custom design drawing, component specification list, and management recommendations. The knowledge base was derived from publications and experts. ASD represents the first attempt to consolidate aeration system design guidelines and procedures for flat grain storage into an expert system. ASD uses illustrations to communicate concepts and terminology more clearly with users. A feature of ASD allows an expert to change the design guidelines and factors. For example, alternative methods of determining the layout and length of ducts can be selected. ASD offers the capability of rapidly designing an aeration system and changing design guidelines to study the effects upon the design. INTRODUCTION rain surpluses and government incentives for producers G who store grain often result in a temporary shortage of grain storage facilities. Grain producers respond by preparing new and existing structures for flat grain storage. These storages require an aeration system to maintain the quality of grain. Although design guidelines for aeration systems are available in extension publications, these guidelines are general and are often not applicable to a producer's specific problem. Grain producers often request help from extension agents, who refer the problem to the state extension specialist or other expert. The availability of an expert in aeration system design is often limited and a means is needed to make this expertise available in county extension offices and sales offices of aeration system component suppliers. The objective of this study was to develop a microcomputer-based aeration system design program (ASD) to simulate the role of an expert in an interactive Article was submitted for publication in November 1988; reviewed and approved for publication by the Food and Process Engineering Div. of ASAE in September 1989. Presented as ASAE Paper No. 88-6057. Trade names are used in this paper solely to provide specific information. Mention of a trade name does not constitute endorsement by the authors, University of Florida, Michigan State University, or W.K. Kellogg Foundation. The authors are D. G. Watson, Assistant Professor, Agricultural Engineering Dept., Institute of Food and Agricultural Sciences, University of Florida, Gainesville; and R. C. Brook, Associate Professor, Agricultural Engienering Dept., Michigan State University, East Lansing. session with a grain producer and to design aeration systems for farm-sized flat grain storages. The available knowledge base consists of guidelines and procedures described in engineering handbooks, extension publications, and technical articles in addition to the experience of experts in aeration system design. Expert opinion was obtained by developing a preliminary version of ASD and applying a structured expert review process with nine experts to review ASD (Watson et al., 1988). Important findings of the evaluation were that given the same problem, aeration system designs differ among experts. Differences in the layout of aeration ducts and determining the length of ducts were attributed to two different design methods and vague guidelines in the literature, respectively. ASD was developed using the application development model described by Watson et al. (1986). The model divides the development of an application into four components: 1) interview, 2) calculation, 3) design drawing, and 4) management recommendations. The model encourages the selection of software development tools which are best suited for each component. By linking the components, the application executes as one program. Since the result of this study is a computer program, the methodology and discussion of ASD are presented using the same organization as the application development model. INTERVIEW COMPONENT The interview component is used to query users about the design problem and educate the user as needed. An interactive program development tool, INTPRO, described by Peterson et al. (1988) was used to implement the interview component. An ASCII text file was prepared for INTPRO to use in executing the interview component. The text file describes the questions, help information, order of screens, consistency checks among responses, and external programs which are used by ASD. Besides information required to size and place aeration equipment, screens were included to request information about the structure to verify post-size requirements. Information screens were described that display the results of intermediate calculations such as post sizing and storage capacity. Illustrations are used to supplement text and increase the efficiency of communication (figs. 1 and 2). Illustrations are based on line-drawings and digitized slides and have been prepared for black and white, 16 color, and 256 color computer display systems. Vol. 6(2):March 1990 © 1990 American Society of Agricultural Engineers 0883-8542 / 90 / 0602-0183 183