Abstract

In this thesis, we study the synthesis of fault recovery procedures using discrete-event models. It is assumed that the faults are permanent and that a diagnosis system is available that detects and isolates the faults with a bounded delay. Thus, the combination of the plant and the diagnosis system, as the system to be controlled, will have three modes: normal, transient and recovery. Initially, the plant and thus the system to be controlled, are in the normal mode. Once a fault occurs in the plant, the system (to be controlled) enters the transient mode. After the fault is diagnosed by the diagnosis system, the system enters the recovery mode. We study the design of a nonblocking supervisor that enforces the specifications of the system in all three modes. The solution is obtained by first transforming the problem to an equivalent Robust Nonblocking Supervisory Control Problem under Partial Observation (RNSC-PO) and then solving the robust control problem.