INTERDEPENDENCE BETWEEN SAFETY-CONTROL POLICY AND MULTIPLE-SENSOR SCHEMES VIA DEMPSTER-SHAFER THEORY

The Dempster-Shafer (D-S) theory has been gaining popularity in fields where incomplete knowledge is a factor. This paper explores the application of the D-S theory in system reliability and safety. Inappropriate application of the D-S theory to safety-control policies can degrade plant safety. This is proven in two phases: 1) A new unified combination rule for fusing information on plant states given by independent knowledge sources such as sensors or human operators is developed. 2) Combination rules can not be chosen in an arbitrary manner; ie, the best choice of combination rules depends on whether the safety-control policy is fault-warning or safety-preservation.