Simultaneous reliable regulation in decentralized control systems

This paper addresses the design of a regulator for a linear, time-invariant plant described by a finite set of models. The regulator must guarantee closed loop asymptotic stability along with signal tracking and disturbance rejection. The control system has to be reliable. This means that it enjoys these properties both when all the instrumentation is in operation, and, at their maximum possible extent, when some sensors and/or actuators faults occur. The faults cause the opening of some feedback loops. In a sense, a single regulator has to be found, which is able to solve a certain number of classical regulator problems at the same time. Referring to a fully decentralized control structure, the paper presents a constructive necessary and sufficient condition for the problem to admit a solution when the exogenous signals are steps.