Intelligent Alarm Handling

Abstract

The paper outlines the functional structure of an intelligent alarm system. The alarm system should be regarded as a "joint cognitive system" where the operator's need for information at different abstraction levels is taken into account. The alarm system is divided into a low level alarm handling module, a human operator interface and a superior decision support level. The superior level is further decomposed into modules for: event analysis, diagnosis, goal selection, planning and execution. The module for event analysis is subjected to further analysis. We propose that this module should combine information on incoming alarms with other information on the process state available from the process control system. We describe how this may be achieved by using a newly developed method based on the parsing of the incoming event sequence. The parsing process is based on a DCG grammar the describing causal relations in the plant. Parameter passing and calls to Prolog clauses are applied to propagate additional constraints and build a parse tree. The parse tree is used to give a hierar chic description of the actual process state . The levels in the tree correspond to different abstraction levels in the description of the process state.