Incorporating Risk into Control Design for Emergency Operation of Turbo-Fan Engines

The paper describes a risk function based approach to constrained turbo-fan engine control to facilitate aircraft emergency maneuvering during take-off or landing. With this approach, the pontwise-in-time state and control constraints limiting the engine thrust response can be intelligently relaxed depending on the individual engine condition monitoring. The proposed control functionality uses the barrier Lyapunov functions, the predictive reference governor and functional limiters. The approach is illustrated using simulations on a linearized and on a fully nonlinear NASA C-MAPSS40k turbo-fan engine model. The capability and flexibility of the design approach to provide fast thrust response while handling multiple constraints, that may be time-varying and dynamically changing, by coordinating multiple engine actuators is demonstrated.