tailieunhanh - An Introduction to Intelligent and Autonomous Control-Chapter 16: A Framework for Knowledge-Based Diagnosis in Process Operations

Tham khảo tài liệu 'an introduction to intelligent and autonomous control-chapter 16: a framework for knowledge-based diagnosis in process operations', công nghệ thông tin, quản trị web phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 16 A Framework for Knowledge-Based Diagnosis in Process Operations . Prasad . Davis Department of Chemical Engineering and Laboratory for Al Research 140 W. 19th Avenue The Ohio State University Columbus Ohio 43210. e-mail davis@ Abstract Process control computers can be extended to include automated diagnosis through the integrated use of Artificial Intelligence techniques. Diagnosis a complex reasoning activity is first characterized and then decomposed into its constituent informationprocessing tasks IPTs . Each IPT is described in terms of input output knowledge representation and inferencing strategy. Examples drawn from practical implementations of knowledge-based systems are used to illustrate each IPT. How these IPTs interact and are integrated to form a framework for constructing knowledge-based diagnostic systems is described. It is shown how this task-based approach provides a natural basis for pulling together a variety of technologies such as neural networks statistical methods conventional numerical methods and knowledge-based systems into a comprehensive system for automated diagnosis. 1. INTRODUCTION In response to demands for increased production levels and more stringent product quality specifications the intensity and complexity of process operations have been rising steadily. To alleviate the operating requirements associated with these demands plants have increasingly relied upon automatic control systems. It is well-known that control systems traditional analog devices or the more recent distributed control systems DCSs are effective for automatically making local process changes within some range to establish or maintain operating conditions in the face of well-defined disturbances. Even with highly sophisticated DCSs it is however clear that processes are subject to equipment failures and unexpected changes in conditions that often result in off-spec To whom all correspondence should be addressed 402 INTELLIGENT