Expert Systems in Technical Diagnostics

Abstract

Modern measurement technology makes it possible to continuously observe and record signals connected with the courses of technological processes, and machinery or devices which take part in these processes. Most often, the signals are supplied to modules which analyse them in order to estimate a set of their features forming the symptoms of the present technical state of the observed object. A particular property of the problems of technical diagnostics is that they are usually related to objects (e.g., machines) of different constructions. It requires a distinction between the forms of databases, and specialisation of rule sets applied within an inference process dealing with the technical state of the object. Additional difficulty is that the history of changes occurring in the observed objects (e.g., modernization) and the history of their maintenance (e.g., repair and control) must be recorded and taken into account in the inference process. The need for applying monitoring and diagnosing devices to complex technical objects is the main reason for research whose goal is to find proper tools for aiding the processes of the design and maintenance of such devices. Interpreting the results of signal analysis is a difficult task. It always requires some kind of experience regardless of the fact that the diagnosing is based on an exhaustive model of the object or on diagnostic rules which are considered to be valid for a determined class of machinery.