Improved clearance of flight control laws using hybrid optimisation

A hybrid optimisation approach to the clearance of flight control laws for highly augmented aircraft is described. The approach is applied to the problem of evaluating a nonlinear clearance criterion for a detailed simulation model of a high performance aircraft with a delta canard configuration and a full authority flight control law. The proposed combination of local and global optimisation methods is shown to offer significantly reduced computation times when compared with using global optimisation methods alone. The accuracy (i.e. closeness to the global solution or true worst-case behavior) of the clearance results derived using the hybrid scheme is also shown to be better than that achieved using either local or global methods on their own