PHM as a Design Variable in Air Vehicle Conceptual Design

Flight critical systems in air vehicles achieve required reliability through different redundancy design techniques including physical system redundancy. Prognostics and health management technology provides the opportunity to eliminate some of the physical redundancy (and associated weight) through implementation of accurate remaining useful life (RUL) algorithms. Consideration of this subsystem design approach upfront during the conceptual design process rather than downstream during the detailed design phase of the air vehicle system may produce a more optimal air vehicle configuration with regard to reliability and weight. Results are presented for an unmanned air vehicle design optimization which included RUL algorithm confidence, control surface actuator redundancy and control surface configuration as optimization variables. Optimization constraints included landing dispersion, mission reliability and mission availability. Reductions in air vehicle weight were achieved with reasonable RUL accuracy requirements.