Stability under sensor or actuator failures

The authors consider the standard linear, time-invariant, multi-input multi-output unity-feedback system with possible failures in the sensor or actuator connections. They parametrize the set of all controllers such that the closed-loop system is stable when sensors or actuators fail. Two classes of failures are considered: the failure of one connection and the failure of any number of connections provided that at least one connection does not fail. The general parametrization requires knowledge of the failure to update the stabilizing controller. For plants that can be decoupled, a class of controllers is outlined which ensure stability under any sensor or actuator failure without updating for different perturbations.