A fault tolerant optimal flight control system

Most aircraft have excess control power which can be used when required; this excess power can allow an alternative to the duplication or triplication of the control linkages, and such an approach is taken in this paper to give rise to a fault-tolerant autopilot design. Although a level of redundancy is inevitable in a realistic design, the authors show that it is possible to reconfigure and distribute the forces and moments of a failed control surface to the remaining functional surfaces. In this way good control performance can be maintained without resorting to redundancy in the actuator and servo hardware