Verification of a Nonlinear Upset Recovery Control Law using Scenario Optimisation⋆

Modern aircraft have several safety features to ensure that all flight parameters remain in their normal operating range. However, if the aircraft diverges from desired conditions, it enters an upset condition in which the flight dynamics are highly nonlinear and integrity of the aircraft is endangered. In upset conditions, nonlinear control laws are hence necessary to handle the nonlinear dynamics. Verification of such nonlinear flight control laws is not a trivial task as common verification methods only apply to linear control systems. The contribution of this paper is to formulate a scenario optimisation method for verification of an exemplary, switching-based upset recovery control law. In addition, we propose a two-step optimisation approach to solve the problem efficiently. Our method is applicable to arbitrary nonlinear control laws given that a simulation model is available. Here, simulations were conducted using the Generic Transport Model, a high-fidelity flight dynamics simulation developed by NASA.