Time-constrained diagnosis using hierarchical models

An architecture, Tilde (time-limited diagnostic environment) has been developed specifically to investigate time-constrained hierarchical diagnosis. Diagnosis is first performed at the most abstract level and is progressively deepened as time allows. Thus Tilde´s objective is to find the most `profitable´ search route through a hierarchical candidate space within a given deadline, the system has been implemented with an existing model based diagnostic tool (ODS-PI). To this has been added a supervisor which directs the hierarchical search, and reviews deadlines. The current implementation has been tested on a two level model of a crude oil distillation plant