Reliable control using redundant controllers

This paper presents a methodology for the design of reliable control systems by using multiple identical controllers to a given plant. The resulting closed-loop control system is reliable in the sense that it provides guaranteed internal stability and H/sub /spl infin// performance (in terms of disturbance attenuation), not only when all controllers are operational but also when some controller outages (sensor and/or actuator) occur. A numerical example is given to illustrate the proposed design procedures.