Nonlinear Robust Performance Analysis of an Aeroelastic System

The problem of analysing the worst-case performance of a nonlinear aeroelastic system is formulated as an optimisation problem and solved using gradient-based local optimisation methods. Two different approaches are considered. The first formulates the optimisation problem in the classical Euler-Lagrange setting and computes the gradient by backward integration of the resulting adjoint system. The second uses a Sequential Quadratic Programming (SQP) method which solves a Quadratic Programming (QP) subproblem at each iteration. The performance of both approaches is evaluated in terms of computational complexity and numerical accuracy, and compared with a standard industrial approach based on gridding the uncertain parameter space. Copyright c 2005 IFAC