A Framework for Active Fault-Tolerant Control of Deterministic I/O Automata

A method for the active fault-tolerant control (FTC) of systems modeled by deterministic input/output (I/O) automata is presented. In the fault-free case, a given controller moves the system such into a specified target state. The aim of the paper is to construct a framework which guarantees that the target state is reached again after the occurrence of a fault. For this, as usually in active FTC, two steps are performed when a fault is present: 1. Fault detection and identification, 2. Reconfiguration of the controller. In this paper, two existing methods for the fault diagnosis and the reconfiguration for I/O automata are combined in order to obtain an active and completely autonomous FTC framework. It is shown how the methods need to be modified and complemented in order to work conjointly and without any inadmissible assumptions on the results of other components. The applicability of the developed method is demonstrated by means of an example featuring a manufacturing cell.