Reliable regulation in the presence of bounded exogenous signals

Addresses the design of a reliable control system for a linear, asymptotically stable plant. Specifically, the considered problem consists of finding a compensator which, besides guaranteeing closed loop asymptotic stability and zero error regulation for bounded exogenous signals when all the instrumentation behaves properly, also ensures that these properties are preserved, at their maximum possible extent, when some sensor and/or actuator failures occur, that is, some of the feedback loops open. Thus, a unique regulator has to be found, able to contemporarily solve a certain number of classical regulator problems. Having presented solvability conditions for both centralized and decentralized control structures, explicit expressions for the relevant regulators are given. These regulators are of the least order, characterized by a small gain and supply the control systems with a generalized form of the unconditional stability property.