INTEGRATED SYNTHESIS OF A PROCESS AND ITS FAULT-TOLERANT CONTROL-SYSTEM

The previously developed method for integrated process and control system (IPCS) synthesis (Hangos et al., 1994) has been extended to the cases for which process safety or reliability is of primary concern. An unambiguous representation of the resultant integrated process and fault-tolerant control system structure, IPFCS structure in brief, is rendered possible through the CP-graph originally proposed for IPCS synthesis. A new axiom for the fault-tolerant controllability is established; it states that more than one independent control path are required for each controlled variable. The fundamental combinatorial algorithm of IPCS synthesis, i.e., algorithm CMSG, has been revised so that the modified set of axioms is capable of identifying the controllable, fault-tolerant structures of an IPFCS synthesis problem. The efficacy of the proposed method for IPFCS synthesis method is demonstrated with a relatively simple example by systematically varying the level of the fault tolerance.