Stability of feedback systems with sensor or actuator failures: analysis

Abstract This paper studies the linear, time-invariant, multi-input multi-output unity-feedback system with possible failures in the sensor or actuator-connections. The purpose of this paper is to analyse the system with failures in k of the sensor-connections or with failures in m of the actuator-connections and develop conditions for stability, It is shown that if the system is stable for all possible failures of k of the sensor-connections or of m of the actuator-connections, then the plant and the controller must have certain properties explained in terms of denominator-matrices of their coprime-factorizations. These conditions imposed on the coprime-factorizations are important for design of fault-tolerant systems.