Franz Barachini, Norbert Theuretzbacher
Although the technology of expert systems has been developed substantially during the past decade, there still seems to be relatively little application to time-critical problems because of their extensive computational requirements. One application area of particular interest is that of process control. Because this area requires real-time operation, the expert system must operate within the time scale of the process involved. Here we present techniques which have been used to implement PAMELA, a language suitable for building time-critical expert systems. We discuss substantial optimizations of the well known RETE algorithm and present run-time measurements based on these optimizations. Despite the critics on RETE' s real-time behaviour we show that the presented optimizations and extensions will cover the demands of many real-time applications. In order to eflciently support process control applications, some useful language constructs concerning interrupt handling and rule interruption are discussed.