Real-time aspects of expert systems in process control

Over the last few years, expert systems have been applied to process control in increasing numbers. These systems differ from the more traditional type of expert systems, in that they receive their data primarily from plant sensors, operate continuously, and operate under time constraints imposed by their plant. This paper surveys the real-time aspects of a number of such systems. Firstly, the requirements that are particular to, or prominent in, the operation of these systems are discussed. Then a number of real-time expert systems are briefly reviewed with the emphasis placed their real-time architectural features. The paper concludes by summarising the architectural features discussed, and relating them to the requirements described in the first section