Design of Robust Dynamic Inversion Control Laws using Multi-Objective Optimization

Abstract

The design of robust attitude control laws for a civil aircraft with nonlinear dynamic inversion and multiobjective optimization is discussed. Dynamic inversion is a methodology that achieves linearization and decoupled command responses of the closed-loop system via inverse model equations in the feedback loop. Using a linear outer loop controller the desired dynamic behavior is imposed. For tuning the free controller parameters, multi-objective optimization is used. The required robustness is achieved via a multi-model approach, as well as local robustness measures (e.g. gain and phase margins) as optimization criteria. As a new approach, not only the linear controller gains are optimized, but also physical parameters in the inverse model that are considered uncertain in the design model. The resulting control laws are used as inner loops of an autoland system, which was assessed for JAR-AWO requirements and successfully flight tested.