Fault diagnosis and controller re-configuration: an hybrid approach

Fault tolerant hybrid systems made up of a continuous plant supervised by a discrete-event controller are considered in this paper. A set of optimal feedback control functions is defined at the continuous level. The aim of the discrete-event monitoring system, modelled by means of a finite-state automaton, is that of choosing, in the above mentioned set, the best control action to be applied to the plant in dependence of the current plant conditions and of possibly occurred faulty events. Thus, the overall control scheme is a two-level hybrid control scheme. A preliminary analytical study of the stability properties of the hybrid fault-tolerant control scheme is presented.